Membrane phenomena as they relate to the function of nerve cells and their axons are being investigated from the view of kinetic processes associated with ion conduction. At the simplest and most defined level, the lipid bilayer is used as a model to study the properties of synthesized macromolecules that produce "gatable" channels and as an assay tool in which biochemically isolated ion channels from nervous tissue can be reconstituted and identified. In biological membranes the energy requirements for transporting ions against a concentration gradient will be determined in a mammalian epithelium. At the next level admittance measurements during voltage clamp of a single nodal and internodal membrane of a medullated axon will be used to compare linear kinetic models of conduction and describe the membrane dielectric properties as they relate to ion channel gating. In the membrane of nerve cells bodies Ca current and Ca-dependent K current will be characterized by using a specially developed patch technique and by voltage clamp relaxation methods and fluctuation analysis. At the synaptic level of membrane function, the transmitter-receptor properties at an inhibitory synapse (crayfish stretch receptor) will be examined in terms of kinetics, transmitter concentration, and pharmacology. Giant spherical muscle cells (myoballs) having dan ion conductance-induced sensitivity to acetylcholine will be studied with respect to the effects of internal ion manipulations and group specific reagents using a patch technique in combination with volatage clamp relaxation and fluctuation methods. At the highest level of complexity the structure-function relationship of neurons in a vertebrate (catfish) retina will be explored through electrophysiological methods in conjunction with dye marker identification techniques in the electron microscope. Finally the uniformity of sarcomere length in muscle fibrils during contraction will use a fast scanning diffractometer to clarify the interpretation of length-tension data as it relates to the interaction of contractile proteins.